The Warrants were originally issued to Appian with an exercise price of C$4.43 per common share on July 21, 2025, in connection with the senior secured project loan credit facility totaling US$450 million for the development and construction of the Company’s fully permitted, 100%-owned Cariboo Gold Project located in central British Columbia, Canada.

ABOUT OSISKO DEVELOPMENT CORP.

Osisko Development Corp. is a continental North American gold development company focused on past producing mining camps with district scale potential. The Company’s objective is to become an intermediate gold producer through the development of its flagship, fully permitted, 100%-owned Cariboo Gold Project, located in central British Columbia, Canada. Its project pipeline is complemented by the Tintic Project located in the historic East Tintic mining district in Utah, U.S.A., a brownfield property with significant exploration potential, extensive historical mining data, and access to established infrastructure. Osisko Development is focused on developing long-life mining assets in mining-friendly jurisdictions while maintaining a disciplined approach to capital allocation, development risk management, and mineral inventory growth.

For further information, contact:

Sean Roosen
Chairman and CEO
Email: sroosen@osiskodev.com
Tel: +1 (514) 940-0685

Philip Rabenok
Vice President, Investor Relations
Email: prabenok@osiskodev.com
Tel: +1 (437) 423-3644

In Europe:
Swiss Resource Capital AG
Marc Ollinger
info@resource-capital.ch
www.resource-capital.ch

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